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Fig. 1.14 Erosions and dilatations of pattern of acidic volcanics in Bathurst area, New Brunswick.
Original pattern A is shown in Fig.
1.14d
. Writing B for the operator set of eight-neighbor square
logic, these patterns are: (a)
A
3
B
;(d)
A
;(e)
A
L
B
;(f)
A
L
2
B
.
Dimensions of frame are 84 km
84 km. North direction points upward (Source: Agterberg and
Fabbri
1978
, Fig. 1)
ʘ
B
;(b)
A
ʘ
2
B
;(c)
A
ʘ
1.5.2 Minkowski Operations: Bathurst Acidic
Volcanics Example
In mathematical morphology (Serra
1976
;Watson
1975
; Sagar
2013
) various other
operations can be performed on black and white patterns, in addition to those
described in the previous section. An example which involves pattern erosions and
dilatations is as follows: The geology of the Bathurst area in NewBrunswick has been
described by Skinner (
1974
). This area contains volcanogenic massive sulphide
deposits that are related genetically to the occurrence of acidic volcanics of the
Tetagouche Group of Middle-Late Ordovician age. These acidic volcanics were
coded from 2-mi geological maps (scale approximately 1:125,000) for an experi-
mental data base described in Fabbri et al. (
1975
). This pattern was also quantified on
a Flying Spot Scanner at the National Research Council of Canada in Ottawa as a set
of 18,843 black pixels on a square grid with in total 324
320 binary (black or white)
picture points spaced 259 m apart in the north-south and east-west directions
(Agterberg and Fabbri
1978
). The resulting binary image is shown in Fig.
1.14d
.
According to Skinner (
1974
), the stratigraphy and structure of the Tetagouche
Group had not been determined and, originally, mapping was based on lithological
units without stratigraphic significance. These units were characterized by
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